Problem: Find the output, $f$, when the input, $t$, is $7$. $f = 2t - 3$ $f=$
Solution: To find the output, ${f}$, we need to substitute ${7}$ into the equation for ${t}$. $\begin{aligned} {f}&=2{t} -3\\\\ {f}&=2\cdot{7} -3\\\\ &=14-3\\\\ &={11} \end{aligned}$ When the input is $7$, the output is $11$.